# std::range-default-formatter<std::range_format::set>

From cppreference.com
< cpp‎ | utility‎ | format‎ | ranges formatter

Defined in header `<format>` |  |
template< ranges::input_range R, class CharT > struct /*range-default-formatter*/<range_format::set, R, CharT>; |  | (since C++23) (exposition only*)

The class template /*range-default-formatter*/ for range types is specialized for formatting range as a set of keys if std::format_kind<R> is std::range_format::set.

### Member types

Member | Definition
`maybe-const-set` (private) | `fmt-maybe-const`<R, CharT> (exposition-only member type*)

### Data members

Member | Definition
`underlying_` (private) | the underlying formatter of type: std::range_formatter<std::remove_cvref_t< `` ranges::range_reference_t<`maybe-const-set`>>, CharT> (exposition-only member object*)

### Member functions

(constructor) | constructs a `range-default-formatter` (public member function)
parse | parses the format specifier as specified by range-format-spec (public member function)
format | writes the range formatted output as specified by range-format-spec (public member function)

## std::range-default-formatter<std::range_format::set>::range-default-formatter

constexpr /*range-default-formatter*/(); |  |

Equivalent to a call to underlying_.set_brackets(STATICALLY_WIDEN<CharT>("{"), STATICALLY_WIDEN<CharT>("}"))

where STATICALLY_WIDEN<CharT>("...") is "..." if `CharT` is char, and L"..." if `CharT` is wchar_t.

## std::range-default-formatter<std::range_format::set>::parse

template< class ParseContext > constexpr auto parse( ParseContext& ctx ) -> ParseContext::iterator; |  |

Equivalent to return underlying_.parse(ctx);.

Returns an iterator past the end of the range-format-spec.

## std::range-default-formatter<std::range_format::set>::format

template< class FormatContext > auto format( maybe-const-set& r, FormatContext& ctx ) const -> FormatContext::iterator; |  |

Equivalent to return underlying_.format(r, ctx);.

Returns an iterator past the end of the output range.

### See also

formatter (C++20) | defines formatting rules for a given type (class template)
range_formatter (C++23) | class template that helps implementing std::formatter specializations for range types (class template)

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/utility/format/ranges_formatter/range_default_formatter_set&oldid=176173"